The diversity of Escherichia coli serotypes and biotypes in cattle faeces
The diversity of Escherichia coli serotypes and biotypes in cattle faeces
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DOI：
10.1111/j.1365-2672.2004.02501.x
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发表时间：
2005-01-01
影响因子：
4
通讯作者：
McSweeney, CS
中科院分区：
文献类型：
--
作者：
Bettelheim, KA;Kuzevski, A;McSweeney, CS
目的：研究不同日粮牛粪便中共生大肠杆菌种群的多样性。方法与结果：30头婆罗门杂交阉牛先饲喂高粒（80%）饲粮，然后随机分为3个饲粮处理组，分别饲喂80%谷物、粗料和粗料+ 50%糖蜜。从每只动物粪便样本的初级分离板中选出多达8种不同的大肠杆菌分离株。从474株大肠杆菌分离株中鉴定出52种不同的血清型，包括9种不同的VTEC菌株。饲喂粗饲料+糖蜜饲粮的牛血清型多样性（已确定30种血清型）高于饲喂粗饲料或谷物的牛（分别确定21种和17种血清型）。聚类分析表明，饲粮为粗饲料和粗饲料+糖蜜饲料的牛分离的血清型与饲粮为谷物的牛分离的血清型关系更为密切。在20种不同血清型的分离株中检测到对11种抗微生物药物中的一种或多种耐药。虽然只有2.3%的大肠杆菌分离株产生肠溶血素，但发现25%产生α溶血素。结论：牛粪便中存在不同的非vtec大肠杆菌血清型种群，饲料可能影响种群多样性。研究的意义和影响：本研究为牛粪便中优势大肠杆菌种群的血清型多样性和表型性状提供了新的信息，牛粪便可能是环境污染的来源。
Aim: To study the diversity of commensal Escherichia coli populations shed in faeces of cattle fed on different diets.Methods and Results: Thirty Brahman-cross steers were initially fed a high grain (80%) diet and then randomly allocated into three dietary treatment groups, fed 80% grain, roughage, or roughage + 50% molasses. Up to eight different E. coli isolates were selected from primary isolation plates of faecal samples from each animal. Fifty-two distinct serotypes, including nine different VTEC strains, were identified from a total of 474 E. coli isolates. Cattle fed a roughage + molasses diet had greater serotype diversity (30 serotypes identified) than cattle fed roughage or grain (21 and 17 serotypes identified respectively). Cluster analysis showed that serotypes isolated from cattle fed roughage and roughage + molasses diets were more closely associated than serotypes isolated from cattle fed grain. Resistance to one or more of 11 antimicrobial agents was detected among isolates from 20 different serotypes. Whilst only 2.3% of E. coli isolates produced enterohaemolysin, 25% were found to produce alpha-haemolysin.Conclusions: Diverse non-VTEC populations of E. coli serotypes are shed in cattle faeces and diet may affect population diversity.Significance and Impact of the Study: This study provides new information on the serotype diversity and phenotypic traits of predominant E. coli populations in cattle faeces, which could be sources of environmental contamination.